Thermistor flow path

ABSTRACT

A fluid pump includes a pump element in communication with an inlet and an outlet. Rotation of the pump element generates a suction at the inlet and pressure at the outlet. The suction and pressure cooperate to move a fluid through a fluid path. An accessory fluid path is in communication with the inlet and outlet. The accessory fluid path includes a thermistor in communication with the accessory fluid path. The thermistor monitors a temperature of the fluid within the accessory fluid path.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/590,248, filed on May 9, 2017, entitled “THERMISTOR FLOW PATH,” whichclaims priority to and the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 62/342,615, filed on May 27, 2016,entitled “THERMISTOR FLOW PATH,” the entire disclosures of which arehereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to fluid pumps, and morespecifically, fluid pumps with a temperature sensing mechanism.

BACKGROUND OF THE INVENTION

Fluid pumps can be included within various fluid reservoirs for moving afluid from within the reservoir to within another portion of themechanism. Such pumps are configured to be submerged within thereservoir.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a fluid pump includesa pump element in communication with an inlet and an outlet. Rotation ofthe pump element generates a suction at the inlet and pressure at theoutlet. The suction and pressure cooperate to move a fluid through afluid path. An accessory fluid path is in communication with the inletand outlet. The accessory fluid path includes a thermistor incommunication with the accessory fluid path. The thermistor monitors atemperature of the fluid within the accessory fluid path.

According to another aspect of the present invention, a fluid pumpincludes a pump element in communication with a fluid path. An accessoryfluid path defines a portion of the fluid path. A shadow port is incommunication with the pump element, wherein the pump element and theshadow port regulate a flow of a fluid between a primary flow of thefluid to an outlet. An excess flow of the fluid to the accessory fluidpath, wherein operation of the pump element in conjunction with theshadow port, promotes the primary flow of the fluid toward the outletand simultaneously promotes the excess flow of the fluid through theaccessory fluid path. The excess flow of the fluid through the accessoryfluid path directly engages a thermistor disposed within the accessoryfluid path. The thermistor measures a fluid temperature of the excessflow of the fluid within the accessory fluid path.

According to another aspect of the present invention, a method ofoperating a fluid pump includes activating a pump element to draw afluid into a fluid path. The pump element operates to direct a fluid toa position that defines a shadow port having an orifice. The fluid isdivided into a primary flow of the fluid toward an outlet of the fluidpath and an excess flow of the fluid through the orifice and into anaccessory fluid path. The excess flow of the fluid is directed to athermistor. A fluid temperature of the excess flow of the fluid in theaccessory fluid path is measured. The excess flow of the fluid isdirected toward one of an inlet and the outlet of the fluid path.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a first perspective view of a fluid pump incorporating anaspect of the thermistor fluid path;

FIG. 2 is a second perspective view of the fluid pump of FIG. 1;

FIG. 3 is a cross-sectional view of the fluid pump of FIG. 1 taken alongline III-Ill;

FIG. 4 is a cross-sectional view of the fluid pump of FIG. 3illustrating a flow of a fluid through the thermistor flow path;

FIG. 5 is a perspective view of a printed circuit board (PCB) housingassembly for a fluid pump that incorporates an aspect of the thermistor;

FIG. 6 is a cross-sectional perspective view of the PCB housing assemblyof FIG. 5, taken along line VI-VI; and

FIG. 7 is a schematic flow diagram illustrating a method for operating afluid pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the invention as oriented in FIG. 1. However, itis to be understood that the invention may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventive conceptsdefined in the appended claims. Hence, specific dimensions and otherphysical characteristics relating to the embodiments disclosed hereinare not to be considered as limiting, unless the claims expressly stateotherwise.

As shown in FIGS. 1-6, reference numeral 10 generally refers to aprinted circuit board (PCB) housing assembly for a fluid pump 12 thatincorporates a thermistor 14 for measuring the temperature of fluid 16being passed through the fluid pump 12. The fluid pump 12 includes apump element, such as a generated rotor or gerotor 18, or other similarpositive displacement pump, in communication with an inlet 20 and anoutlet 22 of the fluid pump 12. Activating rotation of the gerotor 18generates a suction 24, or inward pressure, at the inlet 20 that drawsfluid 16 into the fluid path 26 and outward pressure 28 at the outlet 22that pushes fluid 16 out of the fluid path 26. The suction 24 andoutward pressure 28 generated through operation of the gerotor 18cooperate to move the fluid 16 through the fluid path 26. An accessoryfluid path 30, which defines a portion of the fluid path 26, is disposedin communication with the inlet 20 and outlet 22. The accessory fluidpath 30 includes the thermistor 14 that is placed in communication withfluid 16 flowing through the accessory fluid path 30. The thermistor 14is adapted to monitor a temperature of the fluid 16 moving through theaccessory fluid path 30 of the fluid pump 12.

Referring again to FIGS. 1-6, a fluid pump 12, such as an electric oilpump, generally provides lubrication and cooling to various mechanisms,such as a gear box, differential unit, or other similar mechanism. Thefluid pump 12, typically in the form of a gerotor 18, brushless DC(BLDC) electric motor, and a controller can be fully integrated into ahousing assembly that manages the sealing, thermal transfer and partassembly for the electric fluid pump 12. The fluid pump 12 can include arotor 40 and stator 42 that make up the motor 44 for the fluid pump 12.A drive shaft 46 is driven by rotation of the rotor 40 and serves torotate the gerotor 18 for generating the suction 24 and outward pressure28 for moving fluid 16 through the fluid path 26 and, in turn, theaccessory fluid path 30.

Referring again to FIGS. 1-6, the accessory fluid path 30, in the formof a thermistor flow path 50, serves to provide a fluid pump 12 with atemperature sensing functionality for providing real time measurementsregarding fluid temperature during operation of the fluid pump 12. Thetemperature sensor can be a thermistor-style leaded component that isinstalled in the same cavity as the rotor assembly 52 that serves todrive the gerotor 18. Typically, this cavity is “wet” as the rotor 40 issubmerged in fluid 16, such as oil. Within the fluid pump 12, the fluid16 moving through the gerotor 18 flows through an outlet shadow port 60having an orifice 62 that helps to regulate and divide the flow of fluid16 through the fluid path 30 of the fluid pump 12, as will be describedmore fully below.

The fluid 16 is divided between a regulated primary flow 54 of the fluid16 and the remaining fluid 16 that defines an excess flow 56 of thefluid 16. In regulating the flow of fluid 16 from the outlet shadow port60 and orifice 62, the primary flow 54 is a predetermined amount of thefluid 16 that is directed to the outlet 22. By dividing the fluid 16,the excess flow 56 of fluid 16 that is not part of the regulated primaryflow 54 of the fluid 16 is directed through the orifice 62 and into theaccessory fluid path 30. In this manner, the gerotor 18 pushes theprimary flow 54 of the fluid 16 through the outlet 22 and simultaneouslypushes the excess flow 56 of the fluid 16 through the orifice 62 andinto the accessory fluid path 30. Directing the movement of the excessflow 56 of fluid 16 helps to ensure that there is a continuous orsubstantially continuous flow of fluid 16 across the thermistor 14.Additionally, this configuration of the accessory fluid path 30 inrelation to the outlet shadow port 60 and orifice 62 also helps toensure that the temperature of the excess flow 56 of the fluid 16 is atleast substantially similar to the primary flow 54 of fluid 16 that isdirected through the outlet 22. This configuration helps to provide realtime or substantially real time temperature measurements of the fluid16.

In this disclosed device, the accessory fluid path 30 is placed incommunication with the outlet shadow port 60 through the orifice 62 thatcontrols the excess flow 56 of the fluid 16 from the outlet shadow port60 and into the accessory fluid path 30. From the orifice 62 at theoutlet shadow port 60, the excess flow 56 of fluid 16 flows around atleast a portion of the rotor assembly 52, but within the housing 64 ofthe fluid pump 12. After passing along the side 66 of the rotor assembly52, the excess flow 56 of fluid 16 is directed along an inner surface 68of the PCB housing assembly 10 where the thermistor 14 is located. Theinner surface 68 of the PCB housing assembly 10 includes contours 70that are configured to direct the excess flow 56 of fluid 16 from thesides 66 of the rotor assembly 52 along the contours 70, into engagementwith the thermistor 14, and to a central portion 72 of the PCB housingassembly 10. In this manner, the contours 70 and central portion 72 ofthe inner surface 68 of the PCB housing assembly 10 at least partiallydefines the thermistor flow path 50 and the accessory fluid path 30. Thecentral portion 72 of the PCB housing assembly 10 is in communicationwith a channel 80 of the drive shaft 46. This channel 80 of the driveshaft 46 extends through the center of the drive shaft 46 and the rotorassembly 52 and up through the gerotor 18 and to a recirculation path 82that recombines the excess flow 56 of the fluid 16 with fluid 16entering the inlet 20. In this manner, the excess flow 56 of the fluid16 is draw back into the inlet 20 by the suction 24 generated by thegerotor 18. The recombined fluid 16 is then delivered via the gerotor 18and is divided into the primary and excess flows 54, 56 of fluid 16 asdescribed above. In this configuration, a portion of the excess flow 56upon leaving the recirculation path 82 may be divided again as part ofthe excess flow 56. It is contemplated that the excess flow 56 from therecirculation path 82 will be sufficiently mixed with the fluid 16entering the inlet 20. Accordingly, the amount of the excess flow 56that is divided again into a portion of the excess flow 56 issubstantially minimal. The effects of a portion of the excess flow 56being directly recirculated again through the accessory fluid path 30 aspart of the excess flow 56 will have minimal effects on the temperaturemeasurements of the thermistor 14.

In various embodiments, the recirculation path 82 may direct the excessflow 56 of fluid 16 from the accessory fluid path 30 to the outlet 22 ofthe fluid pump 12. In this manner, the excess flow 56 can be at leastpartially re-combined with the primary flow 54 of fluid 16 that is movedthrough the outlet 22.

Referring again to FIGS. 1-6, the return path of the fluid 16 within theaccessory fluid path 30 and through the central channel 80 of the driveshaft 46 forces the excess flow 56 of the fluid 16 to flow directly overthe thermistor 14. Accordingly, temperature measurements of the excessflow 56 of the fluid 16 moving through the thermistor flow path 50 canbe taken by the thermistor 14 in real time or substantially in realtime. The amount of fluid 16 moving through the accessory fluid path 30is controlled by the size of the orifice 62 on the high pressure side ofthe fluid path 26. Additionally, the return path of the accessory fluidpath 30 is at a lower restriction to prevent a pressure build-up withinthe motor cavity. In order to deliver the signal from the thermistor 14within the PCB housing assembly 10, terminals 90 are used to connect thethermistor 14 to the PCB housing assembly 10. These terminals 90 aresealed to prevent leaking into the PCB cavity 92 on the opposite side 66of the thermistor 14.

Within conventional fluid pumps 12, very little fluid 16 is moved in andaround the motor cavity. As such, placing a thermostat or othertemperature sensing device within this area provides little, if any,temperature-related information.

Referring again to FIGS. 1-6, the accessory fluid path 30 that providesthe thermistor flow path 50 provides a convenient and accurate mechanismfor measuring the temperature of the fluid 16 flowing through the fluidpump 12 while not diminishing the performance of the fluid pump 12.

It is contemplated that the fluid pump 12 described herein can be usedin various applications that can include, but are not limited to, fuelpumps, oil pumps, water pumps, combinations thereof, and other fluidpumps 12 that may be submerged or non-submerged.

It is contemplated that the PCB housing assembly 10 and terminals 90 canbe incorporated within new pumps or can be manufactured for installationwith after-market pumps.

Having described various aspects of the device, a method 400 isdisclosed for operating the fluid pump 12. This method 400 includes step402 of activating a pump element to draw a fluid 16 into a fluid path26. The pump element operates to direct a fluid 16 to a position thatdefines a shadow port 60 (step 404). The fluid 16 is divided into aprimary flow 54 of the fluid 16 toward an outlet 22 of the fluid path 26and an excess flow 56 of the fluid 16 through an orifice of the shadowport 60 and into an accessory fluid path 30 (step 406). The excess flow56 of the fluid 16 is directed to a thermistor 14 (step 408). A fluidtemperature of the excess flow 56 of the fluid 16 in the accessory fluidpath 30 is measured (step 410). The excess flow 56 of the fluid 16 isdirected toward the inlet 20 of the fluid path 26 (step 412).

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent invention, and further it is to be understood that such conceptsare intended to be covered by the following claims unless these claimsby their language expressly state otherwise.

What is claimed is:
 1. A fluid pump comprising: a pump element incommunication with an inlet and an outlet, wherein rotation of the pumpelement generates an inward suction at the inlet and outward pressure atthe outlet, and wherein the inward suction and outward pressurecooperate to move a fluid through a fluid path; an accessory fluid pathin communication with the inlet and the outlet, wherein an orificedirects a portion of the fluid through the accessory fluid path; and aprinted circuit board having a thermistor in communication with theaccessory fluid path, wherein: the thermistor monitors a temperature ofthe fluid within the accessory fluid path; the pump element and theorifice regulate a predetermined amount of the fluid through the fluidpath and away from the accessory fluid path; the pump element and theorifice also regulate an amount of the fluid in excess of thepredetermined amount that defines an excess flow of the fluid; and theexcess flow of the fluid is directed through the orifice and into theaccessory fluid path.
 2. The fluid pump of claim 1, wherein thethermistor is disposed within the accessory fluid path.
 3. The fluidpump of claim 1, wherein the accessory fluid path includes the orificethat regulates flow of the fluid from the fluid path and into theaccessory fluid path.
 4. The fluid pump of claim 1, wherein theaccessory fluid path extends around at least a portion of a rotor thatdrives the pump element.
 5. The fluid pump of claim 1, wherein theaccessory fluid path extends through a central channel of a drive shaftof the pump element.
 6. The fluid pump of claim 5, wherein the centralchannel of the drive shaft extends through a portion of the pumpelement.
 7. The fluid pump of claim 1, wherein the pump element is apositive displacement pump.
 8. The fluid pump of claim 7, wherein thepositive displacement pump is a generated rotor.
 9. The fluid pump ofclaim 3, wherein the pump element includes an outlet shadow port thatregulates a flow of the fluid through the outlet and through theaccessory fluid path.
 10. The fluid pump of claim 9, wherein the orificeis positioned proximate the outlet shadow port.
 11. A fluid pumpcomprising: a pump element in communication with a fluid path; anaccessory fluid path that defines a portion of the fluid path; a shadowport in communication with the pump element, wherein the pump elementand the shadow port regulate a flow of a fluid between a primary flow ofthe fluid that is directed to an outlet, and an excess flow of the fluidthat is directed through the accessory fluid path and then to theoutlet; wherein operation of the pump element in conjunction with theshadow port promotes the primary flow of the fluid toward the outlet andsimultaneously promotes the excess flow of the fluid through theaccessory fluid path; the excess flow of the fluid through the accessoryfluid path is in thermal communication with a thermistor that isdisposed on a circuit board; and the thermistor measures a fluidtemperature of the excess flow of the fluid within the accessory fluidpath.
 12. The fluid pump of claim 11, wherein the thermistor is disposedwithin the accessory fluid path.
 13. The fluid pump of claim 11, whereinthe thermistor directly engages the excess flow of the fluid within theaccessory fluid path.
 14. The fluid pump of claim 11, wherein the pumpelement generates an inward pressure at an inlet of the fluid path andgenerates an outward pressure at the outlet of the fluid path.
 15. Thefluid pump of claim 11, wherein the pump element is a positivedisplacement pump.
 16. The fluid pump of claim 11, wherein the shadowport includes an orifice that regulates the excess flow of the fluidinto the accessory fluid path.
 17. The fluid pump of claim 11, whereinthe accessory fluid path extends from the pump element and around atleast a portion of a rotor of a pump motor to the thermistor, andwherein the accessory fluid path extends from the thermistor and througha central channel of a drive shaft of the pump motor.
 18. The fluid pumpof claim 17, wherein the thermistor is positioned on a circuit boardhousing, and wherein the circuit board housing defines a portion of theaccessory fluid path that directs the excess flow of the fluid from therotor, into thermal communication with the thermistor and toward theoutlet.
 19. A method of operating a fluid pump, the method comprisingsteps of: activating a pump element to suction a fluid into a fluidpath; operating the pump element to direct a fluid to a position thatdefines a shadow port having an orifice; dividing the fluid into aprimary flow of the fluid toward an outlet of the fluid path and anexcess flow of the fluid through the orifice and into an accessory fluidpath; directing the excess flow of the fluid toward a thermistor inthermal communication with the accessory fluid path; measuring a fluidtemperature of the excess flow of the fluid in the accessory fluid path;and directing the excess flow of the fluid toward one of an inlet of thefluid path and the outlet of the fluid path.
 20. The method of claim 19,wherein the thermistor is positioned within the accessory fluid path.